Apparatus for separation by the action of centrifugal force.



. J. GEE.

APPARATUS FOR SEPARATION BY THE ACTION OF OENTBIPUGAL FORGE.

APPLIOATION FILED NOV.1, 1912.

Patented June 24, 1913.

Bti

WILLIAM JOHN GEE, OF TULSE HILL, LONDON, ENGLAND.

APPARATUS FOR SEPARATION BY THE ACTION OF CENTRIFUGAL FORCE.

Application filed November 1, 1912.

To all whom it may concern Be it known that I, VVKLL AM Jonx GEE, engineer, subject of the King f England, esiding at t8 Kingsrnead road, Tulse Hill, London, S. h, England, have invented new and useful Improvements in Apparatus for Separation by the Action of Centrifugal Force, of which .the following is a specifica tion.

This invention relates to apparatus for separation by the action of centrifugal force, in which the materials to be treated are crushed or powdered or otherwise sutlioiently tinely divided to be suspended in liquid, and are passed together with the liquid, usually water, through a centrifugal separator. v

The invention consists chiefly in imparting to a. freely suspended annular wall of liquid, by positive means, such as rotating blao a considerable circun'iterential velocity along or with regard to the rotating surface upon which the heavier particles or the particles having a higher specific gravity are to be deposited. The annular wall is of oonsidcraljlle thickness and is supported by means of a weir-plate arranged near the outlet end of said drum; the positive means for rotat-ingsaid wall consisting of blades extending radially from a central shaft; into said wall and being capable of adjustment in the radial directi n. Between these blades thereare therefore centripetally unob structed spaces. The annular column of liquid is rotated as far as possible as a whole, at a velocity practically equal to the velocity of the driving means, and it is smoothly and. uniformly impelled instead of being stirred or agitated.

\Vith the present. apparatus, the relative velocity of the liquid with regard to the separating surface may be accurately determined beforehand, independently of the density of the liquid or other varying'factors such as surface friction. Moreover, as the driving blades do not close internally the passage for the liquid, there is absolutely no possibility of the separator becoming clogged. By varying the speeds of the outer drum containing the separating surface and of the internal blades, and their 'ratio to one an other, and by varying the rate of flowtl'irough the apparatus, the proeess'can be accurately ad iusted to fulfil the con- Specification of Letters Patent.

Patented June 2d, 1913.

Serial No. 129,012.

ditions necessary to give the best result with .any material to which the process is applicable The acconunmying drawings illust rate an apparatus suitable for carrying out the improved process.

Figure 1 is a sectional elevation, Fig. '2 a cross section.

The apparatus may consist of a drum or cylinder a mounted so as to rotate on its longitudinal axis with an inlet c at one end and an outlet (Z at th ilzither. weir-plate c near the outlet end with a hole in the middle thereof provides for an annular wall ol liquid to be always retained on the inside of the drum, while rotating at a sullicient speed. Radial blades or vanes f are provided -within but clear f the inner surface of the drum, and may if necessary be adapted to be moved radially so that the grip of these vanes or blades on the wall of liquid may be. varied. The blades or vanes f may be guided in radial slots g of two disks It and i fixed to the shaft l: around which the outer drum is rotated, for instance by means of a. pulley Z, the inner hole of which forms the feeding channel. The vanes may be adjusted by means of links m pivoted at the outer ends: to the wings; and pivotally connected at the inner ends to flanges n of a tubular shaft rotatably mounted upon the hubs of the disks h and 2'. A bolt 0 may be used for fixing the vanes in their adjusted positions. Suitable bearings are provided for supporting the drum upon the shaft and for mounting the shaft. the latter hearings not being shown in the drawing. The pulley for driving the shaft is indicated at 7'). The bottom of the drum is of course provided with one or more openings for the discharge of the liquid.

The method of operating the apparatus may be as follows:-'lhe desired speed ol rotation of the parts is first attained and then preferably clean water is fed into the drum until an ellluent is obtained at the outer end. Water containing the material to be treated is then fed in, whereupon particles of greater specific gravity (For instance, ore concentrates) will be deposited on the inner surface of the drum, while par ticles of lesser specific gravity will remain suspended and pass away with the water at the outlet. \Vhen a sullicient deposit has be n attained the inllow is again l'n'eferaL-ly changed to clear water and the flow of clear water continued until the etiluent clear. The recovered material in the drum is then removed and the operation repeated in some ares it may be found desirable to submit the material to two or lnore successive treatments in order to secure a high degree cf extraction or concentration, and in this way eilaer the etlhlent or the material re covered in the drmn or bothmay he retreated lt will be niujlerstood that it is necessary upon treating any given material for the first time that. some trial must be made in order t adjust the apparatus to give. the est results; that is to say, the highest ellicieney in extraction of heavier particles and the smallest possible admixture of gangue or lighter particles with the concentrates remaining;- in the drum. These adjustn'u-nts may vary for ditt'erent materials, but once the correct conditions have been ascertained for any given material they will as a rule remain constant for that material. It may. tor instance. be arranged that. after the desired charge has accumulated in the drum, and the inflow of clean water has caused the diluent to become clear. the speed of rotation of the vanes or blades be increased. This lllClLtlSCd washing etl'ect will cause the materials deposited on the drum to become resuspended iirthe water and, by reason of the. continued inflow to pass outof the drum, the arrangement being altered at, the time of conuuencing the discharge so as to connect the delivery with asettling tank or reservoir. hen the ettluent from the apparatus is obstr .ad to be as clear as is desired, the increased action of the blades is discontiuued. the discharge end is disconnected from the tanlg' or reservoir, the inflow is reconnected to the untreated material and the cycle of operation is repeated.

It will he. understood that it, is ditlieult to give. exact data as to the correct speeds of rotation of the drum and the water within it respta'xtively. as these will vary for every sample or ore. lint the ditl'erence between the two will alwavs ho a considerable one. as it is not the. object of the invention to produce a very slow: (i rcumterential or spiral movement of the deposited mass along the separating surf ce. but to use a circumferential force which substantially assists the settling of the heavy particl s while continuously tittllyillfl away the lighter particles. It is obvious that if a small circumterential force were used the result aimed at by the present in vention could not be obtained. For instance. in treating a certain wolfram ore. in a fairly tinely divided state. the best-result was ob tained with a speed of drum of 200 revolutions per minute. and a speed of the vanes within the drum of 425 revolutions per minute, the diameter of the drum being in this case 18 inches. In adjusting the apparatus to any given oreythe metallurgist in charge of the machine may conveniently startwith a vane speed of twice the drum speed. If the material discharged 'as concentrates contains gang'ue to'too great an extent, (it will seldom he possible .to obtain a perfectly clean concentrate-a commercially useful result is what to be aimed at) that would indicate that a higher vane speed is required. 011 the otherdiand, if it is observed that the '\\';=.ste \'ater rcntaii'is n'ietallic particles which it deen desirable to save, as well as gangue. the rate offeed should first he reduced. in case it sh wuld happen that the rate oftlow through the drum is too rapid for the full separating effect to ta he place, and it this induction of the rate of How does not stop the less. then a higher drum speed might be l'ttlllll'tijl. The proper' tions of suspended matter to water in the mixture fed into the machine. will also vary with ditlerent materials. l find. it: convenient to connaeuce with a dilute mixture sajr lit-. by weight of suspended solids, and then gradually to increase. the proportion until. the results obtained indicate. that the maximum proportion et suspendtwl solids has been l'ttltlHKl. which the cirrumshuices of the case require. It will generally be est to use as large a pro mrtion of suspended solids as possible. as the etlieieucy of the apparatus. judged from the point of the quantity of ore treated in a given time. depends on this factor to a considerable extent. In some cases also it of inn'iortauee from the point of economy of water. The degn'ee of comminution of the ore will be determined by the. fineness. and to some exteutQt-he friability. of the metallic par icles c ntained therein. The chief aim should be to insure as far as may be eouunereially practicable that the particles f metalli or heavy matter areparted from the lighter material, or gaugu and exist in the mixtrre as separate particles. instead of as rmnposite particles, as they will generally be present as the result of imperfect comminntion. \Vhereas by the present methods the degree. at commitmtion which is commercially practicable is limited by the etfieacy of the concentrating plant. the objectsoughtby this process is to remove all limits as to the degree of comminution. except those which are imposed by the question of cost.

Claims:

I. An apparatus for separating material by centrifugal force comprising a rotary drum provided with a separating surface adapted to receive and retain the particles of material, means for rotating said drum. av weir-plate near the outlet. end of said drum adapted to supporta freely suspended annular wall of liquid, and centripetally naobstructed means for positively rotating said annular wall at a higher velocity than the drum; substantially asset forth.

2. An apparatus for separating ore by centrifugal force comprising a rotary drum provided with a separating surface adapted to receive-and retain the particles of ore, means for rotating said drum, a weir-plate near the outlet end of the drum adapted to support a freely suspended annular wall of liquid, a central rotating shaft in said drum, blades extending radially from said shaft into said annular wall of liquid, there being centripetally unobstructed spaces between said blades, and means for rotating said shaft and blades; substantially as set forth.

3. An apparatus for separating material by centrifugal force, comprising a rotary drum provided with a separating surface adapted to receive and retain the particles or ore, a weir-plate near the outlet end of said drum adapted to support a freely suspended annular wall of liquid, rotary blades extending radially into said annular wall,

there being centripetally unobstructed spaces.

between said blades, and means for adjust ing said blades in a radial direction, substantially as'set'forth.

- 4. An a paratus for separating material by centri ugal force'comprisinga rotary drum provided with a separating surface adapted to receive and retain the'particles of material, a weir-plate near the outlet end of said drum adapted to support a freely suspended annular wall of liquid, rotary blades extending radially into said annular wall, there being centripetally unobstructed spaces between said blades, means for adjusting said blades in a radial direction, and

means for locking said blades in their adjusted positions; substantially as set forth.

An apparatus for separating ore by centrifugal force comprising a rotary drum provided with a separating surface adapted to receive and retain the particles of ore, a weir-plate near the outlet. end of said drum adapted to support a freely suspended annular wall of liquid, a central rotating shaft in said drum, disks on said shaft, there being radial slots in said disks, blades uided in said slots, there being centripeta ly unobstructed spaces between said blades, and links piiotally connecting said blades to said shaft, substantially as set forth.

In testimony whereof I have signed my name to this speeificationin the presence of two subscribing Witnesses.

WILLIAM JOHN GEE.

Q. J. l/VORTH. 

